protractorpro‧trac‧tor /prəˈtræktə $ proʊˈtræktər/ noun [countable] 
Examples
a piece of plastic in the shape of a half-circle, which is used for measuring and drawing angles → set square
ExamplesEXAMPLES FROM THE CORPUS
word sets- After all, this is the unit used on the protractor that we first came across early in our school careers.
- Moira screamed and ran away from him, dropping several books and a protractor.
WORD SETS► Maths
abacus, nounalgebra, nounangle, nounarc, nounarea, nounarithmetic, nounarithmetic, adjectivearithmetic progression, nounaxis, nounbar chart, nounbar graph, nounbase, nounbinomial, nounbisect, verbBoolean, adjectiveC, nouncalculator, nouncalculus, nouncanonical, adjectivechord, nouncipher, nouncircumference, nouncircumscribe, verbcompass, nouncomplementary, adjectivecomputation, nouncompute, verbconcentric, adjectivecone, nouncongruent, adjectiveconical, adjectiveconstant, nouncontain, verbcoordinate, nouncoordinate, adjectivecos, cosine, nouncube, nouncubic, adjectivecurvature, nouncurve, nouncut, verbdeci-, prefixdeviation, noundiagonal, adjectivediameter, noundifferential calculus, noundigit, noundimension, noundomain, nouneccentric, adjectiveellipse, nounelliptical, adjectiveequal, adjectiveequal, verbequals sign, nounequation, nounequilateral triangle, nounexponential, adjectiveexpress, verbexpression, nounface, nounfigure, nounflow chart, nounformula, nounfraction, nounfractional, adjectivefunction, noungeometric, adjectivegeometry, noungraph, noungraphically, adverbgraph paper, noungrid, nounHCF, helix, nounheptagon, nounhexagon, nounhistogram, nounhypotenuse, nounimperial, adjectiveimproper fraction, nouninfinity, nouninformation theory, nouninnumerate, adjectiveinto, prepositioninverse, adjectiveisosceles triangle, nounline graph, log, nounlogarithm, nounlong division, nounlozenge, nounmath, nounmathematical, adjectivemathematician, nounmathematics, nounmatrix, nounmean, adjectivemedian, nounmedian, adjectivemetric, adjectiveminus, prepositionminus, nounminus, adjectiveminus sign, nounminute, nounmultiplication, nounmultiplication sign, nounmultiplication table, nounmultiply, verbN, nounnumber, nounnumerate, adjectivenumeration, nounoblong, adjectiveobtuse angle, nounoctagon, nounoval, nounparabola, nounparallel, adjectiveparallelogram, nounpentagon, nounpercentage, nounperimeter, nounperpendicular, nounpi, nounpictogram, nounpie chart, nounplane, nounplane geometry, nounplus, prepositionplus, nounplus, adjectiveplus sign, nounpolygon, nounpolyhedron, nounpower, nounprism, nounprobability, nounproof, nounproportion, nounproposition, nounprotractor, nounquadrangle, nounquadrant, nounquadratic equation, nounquadri-, prefixquadrilateral, nounradius, nounratio, nounrectangle, nounrectilinear, adjectiverecur, verbrhombus, nounright angle, nounright-angled triangle, nounroot, nounruler, nounscale, nounscalene triangle, nounscatter diagram, section, nounsegment, nounsemicircle, nounset square, nounsine, nounslide rule, nounsolid, adjectivesolid, nounsolution, nounsolve, verbsphere, nounsquare, adjectivesquare, nounsquare, verbsquare, adverbsquarely, adverbsquare root, nounsubset, nounsubtract, verbsubtraction, nounsum, nounsurface area, nounsymmetrical, adjectivesymmetry, nountangent, nounterm, nountheorem, nounthreefold, adjectivetimes, prepositiontrapezium, nountriangle, nountrigonometry, nountwo-dimensional, adjectivevalue, nounvariable, nounvector, nounVenn diagram, nounvertex, nounvertical, adjectivevolume, nounwork, verbX, nounx-axis, nouny-axis, noun
a piece of plastic in the shape of a half-circle, which is used for measuring and drawing angles → set square